Blank Screen in Alma when connecting to Circulation Desk

Question

Whenever one of the staff members logs into a Circulation Desk, the screen turns white and the title of the webpage turns to "Connecting" but never connects. This occurs with all the Circulation Desks that the user has roles for. This has started recently. Reproduced with all browsers.

Answer

Resolved by the customer:

We deleted the sandbox widget from their home page and that appeared to have fixed it. The user does not have an account in sandbox, so perhaps that was the cause.